Heat exchanger



Nov. 25, 1930.

s. J. CHUTE HEAT EXCHANGER Filed Dec. 19,- 1927 2 Sheets-Sheet l a 0 o oo 0 INVENTOR 125 ATTORNEYS 5. J. CHUTE HEAT EXCHANGER Nov. 25, 1930.

2 sheds-sneer 2 Filed D60. 19, 1927 INVENTOR 2 t 71?; ATTORNEYS PatentedNov. 25, 1930 UNITED STATES 4 STANLEY J. CHUTE, 0F RIDGEWOOD, NEWJERSEY, ASSIGNOR TO THE GRISCOM-RUSSELT;

COMPANY, OF NEW YORK, N. Y.,

A CORPORATION OF DELAWARE HEAT EXCHANGER This invention relatestoapparatus for heating or cooling fluids in which the heat is transferredfrom one fluid to another- The apparatus is particularly applicable tothe transfer of heat unaccompanied by-condensation or vaporization ofeither fluid, but it may be used also as either a condenser or a boiler.The apparatus is of that type in which one of the fluids, for example,the fluid to be cooled, is passed through a tubular shell and the otherfluid, which may be termed the working fluid, is passed through aplurality of tubes, that is, a tube bundle ,or tube nest positionedwithin the shell. A

One object of the invention is to provide an apparatus of this characterof small exterior dimensions but having a relatively long path ofmovement for the fluid in the shell, whereby thefluid to be cooled inits passage through the apparatus is kept in continuous motion at asufliciently rapid rate tomost effectively utilize the cooling surfaceand at the same time obtain the desired drop in temperature of the fluidto be cooled.

A further object of the invention is to construct an apparatusof thischaracter providing a plurality of passes for the fluid in the shell inwhich that fluid in its travel throughout the length of a given pass ismaintained in continuous motion in the samedirection instead of in azig-zag direction with a reversing motion as heretofore practiced,thereby avoiding the fluid friction and loss of pres sure which resultwhen the rate offiow is sufliciently rapid tocfliciently utilize theheat transferring surface.

Another object of the invention is to provide a heat exchanger having ashell that is divided into passes of semi-circular cross section, with abalfle structure for causing the fluid in the shell to flowcontinnouslyin the same direction instead of in a zig-zag direction as heretoforecustomary, particularly in heat exchangers having passes of this shape.

A further object of the invention is to pro vide a heat exchanger whichis of simpleconstruction and low in cost-of manufacture, the long wallsof the passages for the fluid in the shell being formed of thin metalshaped to form a baflie of approximately helical shape extending fromend to end of each pass through the shell or casing.

A further object of the invention isto provide a heat exchanger having aplurality of passes for the fluid in the shell inwhich provision is madethroughoutthe length of each pass ii or maintaining the fluid incontinuous motion in the same direction, and in which the bundle or nestof tubesfor the entire tubular shell, including both the baffles fordividing the shell into parallel passes, and the battles for causingcontinuous rotary motion, may be removed from the shell as a unit. Afurther object of the invention is to provide a heat exchanger having aplurality of passes for the fluid in the shell in which the tubes andother parts of the apparatus can freely expand and contract withoutstraining the apparatus or loosening the joints between the severalparts. i

In the accompanying drawings have illustrated an embodiment ofmyinvention actual use. 4

In these drawings: Fig. 1 is a longitudinal section taken vertiallythrough the heat exchanger,

Fig. 2 is a somewhat enlarged transverse vertical section taken on line2-2 of Fig. 1; Fig. 3 is'a perspective view of two adjacent baflleplates for one of the passes, the tube which has been found highlysatisfactory in holes in these plates being omitted for the sake ofclearness;

Fig. 4 is a front view oftwo adjacent batfle plates joined together aschanger; V v Fig. 5 is a plan or top view of these two bafiles showingthe joining oi'the upper pore tion of one baflie to the next; and y Fig.6 is a side view of these hafiles.

in the heat ex-:

for nest of tu My improved heat exchanger will be described in itsapplication to the cooling of oil, the coil passing through the shell,as referred to above, and the working fluid being passed through theinterior of the tubes. It will be understood, however, that the oil maybe passed through the tubes, and the working fluid through the shell ifdesired. It will be assumed that water is employed as the workin fluid.

eferring now to the accompanying drawings, the shell 10 in theembodiment illustrated in cylindrical in cross section and is made ofsteel of suitable thickness to withstand the pressure under which theoil to be cooled is circulated. At each end of the shell is providedwith flanges 11 and 12 respectively, which can conveniently be annularrings cut from thick steel plates and secured to their respective endsof the shell by welding. Near the right hand end of the shell, as

viewed in Fig. 1, is a flanged inlet 13 for the passage of the oil to becooled, and diametrically opposite the inlet 13 is a flanged outlet .14by which the cooled oil is discharged.

The tube su porting plate 15 for the bundle lies 16 is clampedaccordingly against the flange 11 at that end of the shell which is nearthe inlet and outlet for the oil to be cooled, this clamping beingeffected by the bolts 17 which also serve to secure a water head 18 tothe outside of the tube sheet 15. The water head is divided into aninlet chamber 19 and an outlet chamber 20 by means of a artition wall21. This partition terminates 1n the same plane as the flanges of thewater head so that when the head is secured in place a fluid-tight jointwill be made between the partition and the surface of the tube sheet 15.

A flanged inlet 22 communicates with the admission chamber 19, and asimilar flanged outlet 23 is provided for the discharge chamber 20, andby means of these connections the working fluid is supplied to anddischarged from the apparatus.

The tubes of the tube bundle 16 supportedin tube sheet 15 are arrangedin concentric rows, with the tubes in alternate rows staggered as shownparticularly in Fig. All of the tubes are expanded in thetube. plate 15after the manner of boiler tubes to :pro

duce rigid and fluid-tight joints.

' At the opposite end ofthe-shell an end cap 24 is bolted to theflange12. Fluid-tigh joints are providedbetween the end cap24ff "and theflange 12,:as well as in securin the 18 and tube sheet 15 to the angewater head all connected to a floatim head or return drum 25 whosecylindrical walls fit loosely in the shell and end cap 24 to permit freeexpansion and contraction of the water tubes. The return drum iscomposed of a tube sheet The water tubes" of the tube bundle, the lefthand end of the heat exchanger are 26 and a cap 27 which is boltedthereto and which forms with the tube sheet a chamber connecting theopen ends of all of the tubes so that the water entering the chamberfrom one portion of the tubes, is returned through the battles forcausing the oil to travel twice throughout the length of the apparatus,and to assume during each of these longitudinal passes a continuousrotary motion in the same direction. This baflle structure alsoconiprises a longitudinal battle 28 which extends rom the inner surfaceof tube sheet 15 and terminates just short of the tube sheet 26 of thereturn drum. This baflle is a relatively thin metal sheet extending inthe horizontal direction diametrically across the shell 10 and dividingthe interior of the shell into two parallel passageways of equal area.The bafile may conveniently be made of sheet steel and is welded acrossits right hand end 29 where it meets the stationary tube sheet 15 so asto prevent the passage of the oil being cooled and so as tofirmly securethe baflle to the tube sheet for a purpose which will appear hereafter.

The passageway on the upper side of the longitudinal bafile is rovidedwith a continuous winding helical aflle 30 which extends from a pointadjacent the inlet 13 to a point adjacent the end of the longitudinalbafile 28 at the opposite end of the apparatus. In-

' stead of making this helical baflle as a single unitary structure,each turn or vane is made of a separate sheet of metal of the shapeshown in Figs. 3 to 6 inclusive. Each of these elements 31cons1sts of asemi-circular a outwardly from the aperture 32.

he. vanes 30 are-mounted in uniformly {spaced relation upon a core tube35 which extends longitudmally'of the upper passage way above thelongitudinal bafile 28. The

.vanes 30 are arranged with their bases 33 at an angle to the axis ofthe core tube 35, de-

pending upon the pitch which it is desired to give to the helicalchannel formed between the vanes. The bases 33 are then tackwelded tothe surface of the lon itudinal baflle 28 so as to form a fairly closefit therewith. The upper portions of the vanes which have IUU has acircular aperture 32 located approximate1y midway: between the center ofits ilstraight base 33 and the. outer edge of its i'se'mi-circularperipheryi The vanes are each litted or out along a straight line 34extendbeen previously severed by the cut or slit 34; are now ofl'set sothat a portion of one vane is brought into alignment with the oppositeportion of the adjacent vane, and the edges of these two vanes arespot-Welded together,

as indicated at 3,6 in Figs. 1,3 and 5.

By thus positioning and joining the individual vanes a continuoushelical battle is produced extending from a point adjacent the inlet 13to a point adjacent the end of longitudinal bafiie 28 at the oppositeend of the apparatus. A substantially helical channel is produced aboutthe core tube 35 and between the vanes and extending throughout the passabove the longitudinal baflle 28. In order to maintain the vanes in thedesired uniform spaced relationship a plurality. of stay rods 37 passthrough the vanes near their peripheries as may be seen in Fig. 4 andextend substantially from tube sheet to the return drum 25. Spacingsleeves 38 are placed upon these rods between the vanes. A relativelylarge number ofstay rods are used for the sake of strength and to serveas oil deflectors.

. The battles on the lower side of the longitudinal baifle 28 arearranged substantially as described above in connection with thepassageway on the upper side thereof, except that the direction ofrotation of the oil chanucl 39 is reversed. Thehelical channel. betweenthe vanes and. the upper pass is joined to the helical channel 39 of'the lower passageway by the space 40 between the tube sheet 26 of thefloating head and the end of the longitudinal baffle 28.

In operation the oil or other fluid to be cooled ispumped into the inletopening 13 under suflicient pressure to force the oil through thehelical passage at agood rate of flow. Although the passage is long,there is little friction loss for the reason that the direction of flowis continuous throughout the length of the helical channels both in theupper and lower passageways, and except for'the Water tubes andspacinrods is free from obstructions. T lne rapiil circulation causes allparticles ofthe oil to be brought rapidly and repeatedly against thecooling surface under the circulating pressure without dependence uponconvection so that the heating surface is maintained at its maximumefl'iciency of operation. This is a feature of particularimportance inoil coolers for the reason that there is not a great difference intemperature hetWeent-he oil to be cooled and the circulating water, asthe water usually availablefor the purpose is seldom at a temperaturebelow 60 or F.

It will be understood that the water tubes I of the tube bundle 16 passthrough the apertures {11 in the vanes of the helical bat'fle members.These apertures may be made to fit the tubes closely, or they may bemade somewhat larger than the outside diameter of the tubes for thepurpose of securing an automatic scouring action lengthwise of the tubesas disclosed 111 Letters Patent of the United States No. 1,454,053,granted May 8,

1923, to Russell C. Jones and assigned to the same assignee asthe-present application.

The core tube 35 and the corresponding core tube for the lowerpassageway are secured at their left hand endsto the tube sheet of thefloating head .25, and at their right hand ends they are spaced slightlyfrom the stationary tube sheet 15." By reason of this, if there happensto'be any difference in the coeiiicients-of expansion of themetal" ofthecore tube, and of the metal of'the tubes of the tube bundle, thepossibilityof strain on the tube joints is avoided.

The longitudinal bathe 28, as mentioned above, is firmly secured tothestationary tube sheet 15, and the individual vanes forming the helicalbaffles in both the upper and lower oil passageways are individuallyWelded to the continuous longitudinal baflle 28 along their base. lines.Thespacing stay rods 37 which support the. outer edges of the helicabafii'e members are not attached to either tube sheet, thus avoiding thepossibility of-stresses due to unequal expansion and contraction, butbecause the peripheries of the vanes are rigidly spaced by means ofthese rods, and because the bases of the vanes are secured to thelongitudinalbaffle, the entire. baflie 'system possesses a remarkabledegree of rigidity and strength.

It will'thus be understood that the entire baffleflsystem is made anintegral part of the 1 tube bundle and can be removed with the-tubebundle and replaced in the shell without fear of damaging the vanesforming the helical bafflemembers. At the same time becausesemi-circular baffle members are secured to the longitudinal plate 29along straight edges. the individual baffle members are permitted toflex slightly to the temperature stresses serve the additional functionof baffles for impeding the circulation of the oil at the ,outer edge ofthe helical channel, therebv causing the. greater'flow ofthe oil throughthe portions of the channel occupied by the tubes. This is "an importantfeature of the construti'onfor itwould be impractical to arrange thetubes close to the outer edge of the tube sheet 15 on account of theemployment of the floating head construction. \Vithout therods locatedadjacent the shell loo wall, there would be less resistance to the flowof the oil at the outer edge of the helical channels with the resultthat some of the cooling surface would be short-circuited.

It is to be understood that my invention includes all modifications ofmy improved apparatus which fall within the scope of the appendedclaims.

\Vhat I claim as new and desire to secure by Letters Patent of theUnited States is:

1. In an apparatus of the character described, a tubular shell forming achamber for the fluid to be acted upon and having inlet and outletpassages for said fluid at one end of the shell, a plurality of tubeswithin the shell for the circulation of the working fluid, means fordelivering and discharging the working fluid to and from said tubes, aflat longitudinal plate arranged diametrically across the interior ofthe shell and extending substantially from one end thereof to the otherso as to cause the fluid to be acted upon to travel from the inlet tothe opposite end of the shell and thence to return within the shell tothe outlet, an elongated core member extending substantially centrallyof the semi-circular chamber above said longitudinal plate, and a secondsimilar core member positioned in the semi-circular chamber below theplate, a plurality of semi-circular sheets of thin metal each perforatedcentrally and arranged in spaced relation upon the core members in eachof said semi-circular chambers, the bases of said bafile elements beingplaced against the flat surface of said longitudinal plate and arrangedin substantially parallel relation at an angle to the axes of the coremembers, the battle elements each being severed radially-from the coremember to their respective semi-circular edges, and the severed portionsof each element being offset with respect to one another, the severededge of one element being secured to the oppositely directed severededge'of its adjacent element thereby forming a continuous substantiallyhelical passageway throughout the length of each of said semi-circularchambers.

2. In an apparatus of the character described, a shell having aplurality of tubes extending therethrough, a tube sheet at one end ofthe shell for supporting said tubes, a longitudinal plate arrangeddiametrically across the shell and extending lengthwise thereof andsecured to the tube sheet at one cud, a return drum freely movable atthe opposite end of the shell including a tube sheet for supporting thetubes at that end, and supporting a core member extending longitudinallyof the shell above said plate and a similar core member below saidplate, and a plurality of half-circu1ar baflie elements threaded inspaced relation transversely upon said core members. said battleelementsbeing each severed radially from the core member to their respectivecurved edges.

the severed portions of each element being offset with respect to oneanother and tho severed edge of one element being secured to theoppositely directed severed edge of its adjacent element, and the basesof said elements secured to the surfaces of said longitudinal plate,thereby forming a continuous substantially helical passageway within theshell from one end thereof to the other both above and below saidlongitudinal plate, inlet ing lengthwise of the shell and dividing theinterior thereof into two semi-circular chain-- hers, an elongated coremember extending centrally lengthwise of each of said chambers, aplurality of semi-circular bafile elements perforated to receive thetubes of the tube bundle and said core member, said elements beingarranged in spaced parallel relation lengthwise of each of saidSQIlll-(ll'tll ,7 lar chambers at an angle to the axes of the coremembers and having their bases secured to said longitudinal plate, eachof said batllc elements being slit radially from the core member to thearcuate edge of the baflle. and the thus severed portions being otl'sctinto alignment with similar portions of adjacent battles and securedthereto so as to form a substantially helical channel about the coremember in: each of said se1ni-circular chambers. inlet and outletconnections for the shell at one end thereof, and means for connectingsaid helical passageways at the opposite end of the shell so as to forma continuous fluid path through the shell, and a plurality of stay rodsextending longitudinally between the baflle members and arranged inspaced relation around the periphery thereof to support the edges ofsaid members.

4. In an apparatus of the character described, a shell having aplurality of tubes extendin therethrough, a tube sheet at one end of t eshell, a longitudinal baflle arranged diametrically across the shell andextending lengthwise thereof and secured at; one end to the said tubesheet, a plurality of semi-circular battle elements mounted in spacedrelation upon both sides of the longitudinal bafllc and secured theretoat their straight bases, a movable tube sheet at the opposite end of theshell, two core members secured to said tube sheet and extendinglengthwise of the shell on the respective sides of the longitudinalbattle through central perforations in the semi-circular battleelements, the said bafile elements being severed radially from the coremember to their res ective curved edges and the severed portions of eachelement being offset with re- 5 spect to one another and the severededge of one element being secured to the oppositely directed severededge of its adjacent element, thereby forming continuous helical passageways Within the shell on both sides of the longitudinal battle.

In testimony whereof I aifix my signature.

STANLEY J. CHUTE.

